Effects of Nunchaku Exercise for Improving Frozen Shoulder

The goal of this clinical trial is to investigate if nunchaku exercise works to treat adhesive capsulitis, or frozen shoulder in middle-aged or older adults. It will also learn about the adherence of this exercise intervention. The main questions it aims to answer are: * Does practicing nunchaku exercises help reduce shoulder pain and improve shoulder movement? * Do people stick with nunchaku exercises better, and spend more time practicing on their own, compared with standard exercises for alleviating frozen-shoulder? Researchers will compare nunchaku exercise to standard exercises for alleviating frozen-shoulder to see if nunchaku exercise works to alleviate frozen shoulder. Participants will: * Join small group exercise classes for 12 weeks, doing either nunchaku based exercises or standard exercises designed to help relieve frozen shoulder. * Have their shoulder pain and movement checked three times: * before training * after 6 weeks of training, * after finishing the 12 week program, and * 12 weeks after the program ends. * Keep a record of their home practice time.